The datetime we currently use within the logger is `%m/%d/%Y %H:%M:%S`. This is not only is this different in US and Europe, as it has month and date flipped from the European counterpart, it also contains no timezone which can cause problems when crosschecking with other logs. For example, going to `dnf.log` file can show this formatting `2023-03-03T14:00:38+0100`, and we know exactly what timezone it was, but with convert2rhel we cannot say whether it is UTC or the users timezone at a glance.

Proposed solution

• We move to ISO 8601 with the same type of formatting as DNF (2023-04-19T10:04:58+00:00)
• We change logging output for both terminal and log file